Commercial man-made polymeric textiles fibers and filaments may be manufactured continuously from the raw materials to the finished fiber product, but because of the difficulty of synchronizing polymerization and fiber spinning and processing, the fact that many fibers producers do not have the polymerization capability or that in-house polymerization capability is physically remote from fiber spinning and processing facilities, it is quite common to prepare an intermediate polymeric granule or flake in which form the polymer can be easily handled, sold, stored, shipped, and then melted for further processing.
The granulaion of hard brittle material, particularly polymeric material such as polyester polymer, is accomplished commercially only with the finest and hardest of cutters under ideal conditions, preferably utilizing the cooling effect of an underwater operation. Underwater flake cutting, according to methods and apparatus described in such patents as U.S. Pat. Nos. 2,850,764; 3,277,519 and 3,600,745, is well known in the art. Strands are passed through passages and bushings, and upon emerging therefrom, are severed by rotating cutters. Flake cutting machines according to these methods and apparatus, when placed in continuous use, require frequent shutting down and resharpening or replacement of cutters. Production time is lost, and replacement cutters are expensive. Wear and tear on cutters, being of a high order, any method or apparatus by which blade life can be substantially increased or blade wear can be substantially reduced, would be a meritorious advance in the art. Moreover there is a well recognized and long felt need for increased cutter life in these machines.